- Time limit: 1.00 s
- Memory limit: 512 MB
Input
The first input line has an integer $t$: the number of tests. Then each test has the following format:
The first line has two integers $n$ and $m$: the number of nodes and edges. The nodes are numbered $1,2,\dots,n$.
Then there are $m$ lines that describe the edges. Each line has two distinct integers $a$ and $b$: there is an edge between nodes $a$ and $b$.
You can assume that there is at most one edge between two nodes.
Output
For each test, print "YES", if there is a node that belongs to more than one cycle, and "NO" otherwise.
Constraints
- $1 \le t \le 1000$
- $1 \le n, m \le 100$
Input:
2
4 4
1 2
1 3
1 4
2 3
4 5
1 2
1 3
1 4
2 3
3 4
Output:
NO
YES